One of the very few things that helps me tremendously with denationalisation is gardening. Iv been an amateur gardener for quite a while now (before i developed dp) And i did take a few years off.
However back to the point Being amongst plants and nature has got to be one of the most grounding activities you can do - it's a natural therapy. Even if you are just weeding the border. Feeling the wet warm/cold, soil go through your hands, or when you water the plants, the back spray of the water or picking the first tomatoes of the season is incredibly relaxing.
When I'm gardening, it takes my mind of things for a while and i can just be at one with nature. Its much better than video gaming which is my other passion because it gets you outside, and i really do find my dp gets better for a while.
Of course the other aspect to it is although you don't feel great yourself, and may even be severely depressed, the fact that you are nurturing another living thing from seedling to fully fledged plant and producing vegetables or flowers, makes you remember just how precious life is.
If you're not already a gardener I would highly suggest trying it out and see if you like it, it may help you.
Or you could simply go for a nice walk through the fields, or anywhere you want.
Thanks for reading.